Holography may generally be divided into two categories: optical holography and computer-generated holography. The computer-generated holography (CGH) uses computer to digitally generate coding information of the holographic image, and then reconstructs optical paths from coding information of the holographic image to display the holographic images. In computer-generated holography, view window type of the holographic display plays an important role. The primary goal of the view window type of holographic display is to reconstruct only a portion of wave-front that can be seen directly by a viewer. This portion of the wave-front is a surface section of a spherical wave-front, and is also called an observation window. The size of the observation window correlates with the size of viewer's pupil. The viewer can view a complete reconstructed three dimensional (3D) scene through the observation window.
FIG. 1 is a diagram illustrating an operation principle of a conventional view window type of holographic display. Computer generates encoded data of an object or a hologram, and displays the encoded images calculated corresponding to the coding information of the holographic image. That is, light transmittance of each pixel of a holographic display is calculated based on the coding information of the holographic image.
As shown in FIG. 1, light emitted from a light source 1 passed through a lens 2 and converged on a display screen 3, passes through each pixel of the display screen 3, and displays an image in an observation window 4. When a viewer positions an eye at the observation window 4, the viewer may see a complete 3D scene. The view window type of holographic display does not require coding information of the holographic image for each position on the viewing plane of the viewer. Thus, the amount of computing is reduced.
However, such holographic display method only displays images to one eye of the viewer, and gives the viewer a less, desired viewing experience.
The disclosed holographic display device and holographic display method are directed at least partially alleviate one or more problems set forth above and to solve other problems in the art.